Pay close attention to your bell crank geometry. If your bell crank holes line up with the hinge line, then the servo bell crank should line up with the servo pivot point. If its 1/8" behind the hinge line, then the servo holes should be 1/8" behind the servo pivot point. And so on. If they are not the same you leave yourself open to a line going slack. To some its not a problem, I'm just more annal about it. I also dont use bushinged servos since I keep a fair amount of tension on the lines. You dont have to be guitar string tight, just taught.
Edwin